docs: def _surface_escape(code, char):
          """Return *code* with *char* escaped as an HTML entity.
  
          The main use of this is to escape pipes (``|``) or equal signs (``=``)
          in parameter names or values so they are not mistaken for new
          parameters.
          """
          replacement = str(HTMLEntity(value=ord(char)))
          for node in code.filter_text(recursive=False):
              if char in node:
                  code.replace(node, node.replace(char, replacement), False)